The Russian and Georgian Orthodox churches say they will not take part in a historic meeting of the world's Orthodox churches due to open in Greece in a few days.

The Russian Orthodox Church announced on June 14 that it was calling for a postponement of the Pan-Orthodox Council, slated to be held on the Greek island of Crete from June 17-26.

"In a situation when councils of this level have not gathered for many centuries, maybe it requires more time [to prepare]," Russian Orthodox official Vladimir Legoyda told Rossia 24 television station.

Leaders of the official branches of the Orthodox Church last held such a council in A.D. 787. The Orthodox and Catholic churches officially split in 1054.

Meanwhile, Georgian Orthodox Church Patriarch Ilia II said on June 14 that his church would also not take part in the planned summit, saying "unity of the Orthodox church [branches must first be] achieved."

The Russian and Georgian churches join the Bulgarian Orthodox Church, the Church of Antioch (Syria), and the Serbian Orthodox Church in saying they will not attend the council.

The cancellations put the holding of the long-awaited church meeting -- organized by the head of the Orthodox Church, Patriarch Batholomew I -- in doubt.